Portable data collection devices have been developed for a wide variety of applications and are becoming increasingly popular as a cost effective mechanism by which to perform a number of essential business activities such as inventory data collection and control functions such as automatic product identification and price correlation. While the specific features of such devices vary dependent upon the application, nearly all are designed for and require hand-held use. Virtually all such devices include a microprocessor based control unit, and further include or provide for the optional attachment of an electromagnetic (also known as radio frequency identification or RFID), laser or CCD scanner for automatic identification of items on which suitable, corresponding electromagnetic or optical identifiers such as tags or bar-code labels have been placed.
Significantly, these applications require either substantially continuous hand held scanning over extended periods of time, or repetitious operations where the device must be kept with a mobile operator in a holster-like carrier and frequently and rapidly removed for data-entry in the course of a work session. These requirements, in turn, mandate that the device be as comfortable as possible to minimize fatigue and stress, be sufficiently small to fit within and quickly removed from a holster, and include all desired functionality such as scanning, keypad data entry while hand held and when the device is on a table or desktop, display, radio frequency and modem communications, and long-term battery operation.
These efforts to fulfill such diverse needs have been varied and may be broadly classified as those which electrically connect a physically separate scanner, and those that include the same within the device. In the former instance, exemplified by U.S. Pat. No. 5,023,824, both hands are required for scanning, one to hold the device and the other to hold and operate the scanner. In the latter instance, the components necessary to furnish the required functionality have resulted in devices so wide, heavy and/or out-of-balance as to be stressful and fatiguing to hold for lengthy times, and difficult or impossible to position for successful scanning or employ in holstering operations. Devices having one or more of these limitations may be found in U.S. Pat. Nos. 4,621,189; 4,758,717; 4,983,818; D320,013; D325,574; and the Model BHT-2000 Bar-code Handy Terminal made commercially available in the United States by the Nippondenso ID Systems division of Toyota Tsusho America Inc. of San Mateo, Calif.